Plastic Parts – Laser Cut:
Pololu Corporation -
Provides extremely cost effective laser cutting for most plastics (acrylic, ABS, polycarbonate, acetal, nylon, styrene, gatorfoam, styrofoam, PETG, wood, cloth, and paper. They accept CAD output in several formats including DXF, or even a faxed sketch, and provide you with a PDF estimate of the job.
Their website includes quite a few detailed examples of laser cut parts they have made along with details on the design, materials, and piece part costs. Be sure and check out the two examples of the plastic parts used in their own robot kits.
The five parts shown above are used in their servo driven sumo robot kit. Laser cut from 1/8” acrylic the total cost including cutting, material, and USPS shipping is less than $10.
Printed Circuit Boards:
Developers of the EAGLE circuit board design package. EAGLE stands for Easily Applicable Graphical Layout Editor. The package includes a fully functional layout editor, schematic editor, and autorouter – all integrated and making use of a single user interface so you don’t have any troublesome, error prone conversions between your schematics and layouts. For hobbyists and personal (non-profit) use, CadSoft provides a freeware version – EAGLE Light Edition – that’s fully functional with only a few minor limitations.
- Useable board area is limited to 4 x 3.2 inches (100 x 80 mm)
- Only two signal layers can be used (top and bottom)
- The schematic editor can only create one sheet
Even with those limitations, the EAGLE Light Edition has more than enough power to handle almost all robot hobbyist design needs. They even reference a complex 68HC12 board that was completely designed using the freeware version. And, if for some reason, you really need all the power of the EAGLE Standard Edition they sell a fully functional non-profit, single user license at a discounted price.
Spark Fun Electronics -
Produces custom PCBs from your design files for $2.50 per square inch. No hidden fees, no gimmicks, no minimum sizes or quantities. They even provide free shipping within the US. PCBs are 2–layer with white silk screen, green solder mask, no limit on the number of vias, no limit on the number of pads or components, and are routed not sheared. Minimum size is 1”x1” and the maximum is 10”x15”.
Their site has detailed instructions on the file format and information required.
Small Parts, Gears, Tools, and Materials:
Small Parts, Inc -
Anything and everything – you name it, there’s a good chance they stock it. Materials like stainless steel, brass, copper, ABS, acrylic, ceramics, … Components like plastic tubing, connectors, o-rings, wire, cable, screws, fasteners, washers, gears, … Tools, including machine tools, hand tools, calipers, screw drivers, gauges, loupes, drills, taps, dies, … They bill themselves as “The Hardware Store for Researchers and Developers”.
Enables you to design your own part using free, down-loadable software, does manufacturability checking to keep you from designing something that can’t be machined, gives you pricing, and allows you to order online. Current capabilities include milling, turning, laser cutting, water-jet cutting, wire EDM, tapping, bending, blanking, punching, plastic extrusion, thermoforming, and injection molding.
Download the CAD/CAM package, install it, then start designing. Here’s a simple block with four holes:
Do a 3D visualization complete with interactive, real-time rotation:
Analyze your part for manufacturability. The software flags problems with your design and where ever possible suggests corrective actions. Once you get the part to pass the analysis, then the software enables you to check the estimated price and delivery for various quantities:
It even suggests potential cost reductions. In this particular case it pointed out that a smaller stock size would reduce the machining cost and time, and that changing the material selection would allow the part to be manufactured on a different machine tool.